let numberRegexp = /^[0-9]+$/;
class ZipCodeValidator {
  isAcceptable(s: string) {
    return s.length === 5 && numberRegexp.test(s);
  }
}

/** This can be a class, interface, namespace, function, or enum.*/
export = ZipCodeValidator;
/** 类似于es6↓*/
// export default ZipCodeValidator;
